Marshmallows are a Terran confection consisting mostly of sugar and egg whites. They are used in many desserts, including Rocky Road ice cream. (ENT: "Oasis")

Traditionally, camping out includes toasting marshmallows over a campfire. After researching the USS Enterprise-A's database, Spock brought a marshmallow, which he referred to as a "marshmelon", dispenser along for his shore leave in Yosemite National Park with Leonard McCoy and James T. Kirk. After consuming a marshmallow, it is traditional to then engage in a sing-along. (Star Trek V: The Final Frontier)